No not good idea. The website is better,because you can add more details information than file. And can create bug report for other theme e.g OSX,QuickTime,iOS sdk,xcode etc...Your forgot to mention the Feedback app on the device itself for bugs as well. You don't have to use their website. If using El Capitan you can also use it's feedback assistant and choose iOS 9 as well by opening the application on OS X, choosing New Feedback, and top right corner choose "change" and choose any beta programmes.